Degradation of diuron by chlorination and UV/chlorine process: Degradation kinetics and the formation of disinfection by-products

• Published in: Separation and purification technology 2018-08, Vol.202, p.365-372
• Main Authors: Xiang, Huiming, Shao, Yisheng, Gao, Naiyun, Lu, Xian, An, Na, Tan, Chaoqun, Zheng, Zhaofang
• Format: Article
• Language: English
• Subjects: Advanced oxidation process; Chlorination; Disinfection by-products (DBPs); Diuron UV/chlorine
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2018.03.073

•Comparison between the degradation of diuron by chlorination and UV/chlorine process.•The relative contribution of active species in UV/chlorine process.•Impacts of different conditions including oxidant dosage, pH, etc. were discussed.•The degradation pathway of diuron during UV/chlorine was proposed using LC-ESI/MS.•The DBPs formation was evaluated during followed chlor(am)ination after pre-chlorination and UV/chlorine process. The degradation of diuron by chlorination and UV/chlorine process and the formation of disinfection by-products (DBPs) was investigated in this study. The degradation of diuron followed the pseudo first-order kinetics model. In UV/chlorine process, hydroxyl radical were proved to provide more contribution in the oxidation. The degradation kinetics increased with the increasing of chlorine dosage and the decreasing of natural organic matter (NOM) dosage. However, the degradation pathways were defined using high performance liquid chromatography coupled with a TSQ Quantum quadrupole mass spectrometer (HPLC-ESI/MS). The formation of DBPs after chlorination and chloramination was defined using gas chromatography with elect ion capture detector (GC-ECD) and gas chromatography–mass spectrometer (GC–MS). Several kinds of DBPs including chloroform (TCM), 1,1-dichloroacetone (1,1-DCP), 1,1,1-trichloroacetone (1,1,1-TCP), trichloronitromethane (TCNM), dichloroacetamide (DCAcAm) and trichloroacetamide (TCAcAm) was identified in this study.